Remove setting for disabling cc touch hit testing.

Source/core/frame/Settings.in

 # Defines properties which are available on the Settings object.
 #
 # Please think carefully before adding a new Setting.  Some questions to
 # consider are:
 # - Should this be a RuntimeEnabledFeature instead? Settings are for things
 #   which we support either values of at runtime.  Features are set at renderer
 #   process startup and are never changed. Features also tend to be set to a
 #   value based on the platform or the stability of the code in question, where
 #   as settings both codepaths need to be stable.
 # - How will you ensure test coverage of all relevant values of your setting?
@@ skipping 130 matching lines @@
 # From Pointer Events spec:
 #   http://www.w3.org/TR/pointerevents/#widl-Navigator-maxTouchPoints
 maxTouchPoints type=int, initial=0
 
 # Whether touch gestures should be "fuzzed" to nearest touch targets.
 # It's expected that this is enabled everywhere by default, but it may be
 # disabled for testing purposes as the algorithm is not yet perfect.
 # crbug.com/304895 tracks removal once we're satisfied with the algorithm.
 touchAdjustmentEnabled initial=true
 
-# A mostly-stable performance optimization. crbug.com/304518 tracks removal.
-compositorTouchHitTesting initial=true
-
 syncXHRInDocumentsEnabled initial=true
 cookieEnabled initial=true
 navigateOnDragDrop initial=true
 DOMPasteAllowed initial=false
 
 allowCustomScrollbarInMainFrame initial=true
 webSecurityEnabled initial=true
 
 # Special keyboard navigation mode intented for platforms with no
 # proper mouse or touch support, such as a TV controller with a remote.
@@ skipping 102 matching lines @@
 
 # This value indicates the maximum number of bytes a document is allowed
 # to transmit in Beacons (via navigator.sendBeacon()) -- Beacons are
 # intended to be smaller payloads transmitted as a page is unloading, not
 # a general (one-way) network transmission API.
 # The spec ( https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/Beacon/Overview.html )
 # does not proscribe an upper limit, but allows for it -- the underlying
 # API will return 'false' in that case.
 maxBeaconTransmission type=int, initial=16384